#2516 - Rowan Jacobsen

**Joe Rogan** (0:03)
The Joe Rogan Experience.

**Jamie** (0:06)
Trained by day, Joe Rogan Podcast by night, all day.

**Joe Rogan** (0:13)
Very nice to meet you, man.

**Rowan Jacobsen** (0:15)
You too, thanks for having me.

**Joe Rogan** (0:16)
And thanks for doing this work, because you want to talk about a subject that's confused so many people. Is the sun good for you? Is the sun killing you? Why does it give you vitamin D if it's bad for you?
Why do people get skin cancer if it's good for you?

**Rowan Jacobsen** (0:30)
Yeah, it's super complicated, and the messaging has not admitted that, and that was a big impetus for the book.

**Joe Rogan** (0:38)
What was your opinion of sun exposure before you started writing this?

**Rowan Jacobsen** (0:43)
So I had inherited the conventional wisdom from the institutions that it was really bad. At the same time, I will admit that my instincts were that, maybe it wasn't as bad as they were leading me to believe, because whenever I was in the sun, I felt good, and I live in Vermont, by the time winter was reaching like month six, I felt bad, right? So I was like, there's more here than we're being told.

**Joe Rogan** (1:10)
Yeah, that was my wife's opinion. She's like, the sun can't be bad. It always feels good when you go out there. I'm like, I don't know. It's a little more complicated than that, but that is the instinct. Like, it feels great when you're in the sun. It's like, your body wants it.

**Rowan Jacobsen** (1:25)
Your body wants it. I mean, we now know that it literally triggers the release of opiates in the brain, sunlight. So yeah, your body wants it and your body rewards you when you get it.

**Joe Rogan** (1:34)
So what is the issue? Well, let's go back to the beginning. So you had this idea that sun exposure is probably giving people cancer and sunscreen is good. You need more sunscreen. Stay out of the sun. So when you started going into the research, what made you shift your opinion?

**Rowan Jacobsen** (1:52)
So it really started for me like seven or eight years ago.
I was on this science journalism fellowship. So I was just doing research and some of those studies hit. The one about opiate release in the brain and other studies showing that when light hits skin, cognition actually improves. Like your metabolism cranks up a little bit when the body feels sunlight coming in. And I thought, that's interesting. That's all good stuff. Then I came across a couple other studies that seemed to indicate that sunlight could lower blood pressure, which was really interesting. So then I still had the sense, sunlight bad, right? So then I remember just like googling, like, so how much does sunlight like shorten your lifespan?
And like the punch line is, sunlight seems to extend your lifespan. So when I hit that, I was like, why are we not hearing this? So that was the beginning.

**Joe Rogan** (2:46)
And so then, so what is the problem? Like, what is the issue with sunlight? Like, when you think about skin cancer, what are the confounding factors that lead to skin cancer? Are we completely aware of that?

**Rowan Jacobsen** (3:00)
It's more complicated than we thought. So sunlight does increase your risk of skin cancer. But depending on the type of skin cancer you're talking about, it's not necessarily like a linear relationship. So, yes, in general, too much sun increases your risk of skin cancer. But yeah, the question is, what are the confounding factors? How important is skin cancer compared to these other things? If sunlight reduces your risk of other diseases, how does that weigh against the risk of skin cancer?
So it's not the type of thing that can be done in a 30-second PSA.

**Joe Rogan** (3:37)
Right, so sun cancer that does cause skin cancer, excuse me, sun exposure that does cause skin cancer, what is causing it? Why is it happening?

**Rowan Jacobsen** (3:48)
So ultraviolet light, which is the most energy-intense part of the solar spectrum, when those photons of light hit your skin, they go inside, right? We absorb all wavelengths of light to a greater or lesser degree, and that super high-energy ultraviolet light, if it hits a DNA molecule, it can mess up the DNA molecule, and then that can lead to mutations and skin cancer. Then it can also indirectly cause skin cancer by creating what are called reactive oxygen species, which are free radicals basically. So it energizes these atoms that start to steal electrons from other atoms and cause a little chain reaction, which is what a free radical is.